Many telephones available on the market today incorporate circuitry capable of dialing pre-selected telephone numbers. The conventional means for accomplishing this task consists of the touching of a single button that triggers the circuitry to access a desired telephone number that is stored in electronic memory. However, the electronic memory circuitry normally requires an outside power source to maintain the storage of the telephone numbers. This type of memory storage is called volatile memory.
It is well known that many individuals have an extremely difficult time programming pre-set telephone numbers in many modem telephone units. The degree of difficulty required to program these devices indicates a need for programming simplicity. A device that simplifies the programming and storage of pre-determined telephone numbers, the dialing process for these numbers, and the elimination of an outside power source, is an improvement over the conventional means for accomplishing standard telephone number dialing using pre-programmed dialing buttons.
The external power source for volatile circuits usually consists of a low-power battery or AC plug-in adapter into the telephone itself. However, a major drawback of volatile memory is the requirement that the electronic power source remain constant. If the external power source is interrupted by insufficient battery power, or a power outage due to an electrical storm, the entire electronic memory used for storing telephone numbers vanishes. Should a typical power loss occur, the entire electronic memory must be reprogrammed with telephone numbers.
Prior inventions have included circuitry to accomplish a non-volatile memory device capable of storing pre-determined telephone numbers. For example, U.S. Pat. No. 5,495,525 issued to Walker et al. ("Walker") teaches a device in which a pre-determined telephone number dialing circuit must be pre-wired. The Walker dialing circuit requires that a digital counter integrated circuit be pre-wired to an integrated dialing circuit so that the telephone number corresponds to a given wiring pattern. When the counter cycles through its full count in binary, the Walker dialing circuit dials a pre-determined telephone number, depending on how the wires have been arranged between the dialer circuit and the counter circuitry. A tremendous limitation on this method is that it precludes the user from changing the telephone number, unless the entire circuit is rewired to correspond to a new telephone number. Rewiring the circuitry requires not only knowledge of electronics and integrated circuits, it also requires that the circuitry not be hard wired on a printed circuit board.
Other patented devices discuss similar approaches to dialing pre-programmed telephone numbers. However, none of these patented inventions include a non-volatile memory circuit that allows the user the flexibility to change or update the pre-determined telephone number by simply changing or reprogramming a read only memory device. The flexibility to allow a user to change a single, or even multiple, telephone numbers is a substantial improvement over the prior art.